• Title/Summary/Keyword: Rod speed

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Temperature Distribution of High Speed Tool Steel Rod During High Speed Hot Rolling Procedure (고속열간압연에서 고속도공구강 봉재의 온도분포 해석)

  • Jeong, Hyo Tae;Lee, Soo Yeon;Ha, Tae Kwon;Jung, Jae Young
    • Korean Journal of Metals and Materials
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    • v.46 no.3
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    • pp.150-158
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    • 2008
  • The temperature distribution of high speed tool steel rod has been studied during high speed hot rolling procedures. The tool steel rod shows severe temperature gradient during rolling procedures and the temperature at the center of rod are much higher than that at the surface of rod. This temperature gradient accumulated after every rolling procedure and the center of rolled rod could be remelt in some procedures to cause inside defects. In this study, the temperature distribution was simulated using finite element method and the processing parameters such as rolling speed, cooling condition, have been discussed to prevent the temperature increases at the center of rod.

Effect of Rolling Speed on the Exit Cross Sectional Shape in Rod Rolling Process

  • Lee, Young-Seog
    • International Journal of Precision Engineering and Manufacturing
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    • v.8 no.1
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    • pp.27-31
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    • 2007
  • A rolling speed dependent spread model is proposed for predicting the exit cross sectional shape in oval-round (or round-oval) pass rod rolling process when the rolling speed is very high. The effect of rolling speed on the exit cross sectional shape is measured by performing a four-pass continuous high speed (${\sim}80m/s$) rod rolling test and is described in terms of the spread correction parameter. The validity of the model is examined by applying it to rod rolling process at POSCO No.3 Rod Mill. The cross sectional shapes of workpiece predicted by the proposed model coupled with the surface profile prediction $method^{6}$ are in good agreement with those obtained experimentally.

Development of Micro Tool using High Speed Etching Process (고속 회전에칭을 이용한 미세공구의 개발)

  • 김성헌;박준민;정해도
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.959-962
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    • 2000
  • In this study, the micro shaft was fabricated by high speed etching process. The integration of the kinetic energy of circumference and the effect of etching takes less time to fabricate the micro shaft than any other conventional methods. First, the end part of the rod(SKD11) was dipped in chemical solution(FeCl$_3$) and the rod rotated at high speed(3500-10000rpm). Experimental setup was simply composed of high speed motor. chemical solution and $\Phi$ 1 mm rod. The main factors of diameter control are chemical concentration, reaction time and rpm. has a result. the diameter of the dipped rod was decreased by 200${\mu}{\textrm}{m}$ by high speed rotation and its shape and surface was good. From this experiment, we found the possibility to manufacture micro shaft without very expensive equipment.

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Die and Mold Making for Connecting Rod Parts through High Speed Machining (고속가공을 통한 커넥팅 로드용 금형 가공)

  • 임유업;김정석;강명창;이득우;정융호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.926-929
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    • 2000
  • Recently, there are lots of applications in machining dies using CAD/CAM systems. which results in reduction of machining time and rising of machining efficiency applying high speed machining and high quality machining. Investigation of machinability is necessary in order to apply high speed machining. In machining complicate 3D model such as connecting rod die. the need of high speed machine and coated tool is requested recently in this field. This paper introduce the database of high speed machining to improve machining efficiency of connecting rod die.

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Propagation Speed of Torsional Waves in a Circular Rod with Harmonically Varying Material Properties

  • Kim, Jin-Oh
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.1E
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    • pp.43-47
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    • 2000
  • The paper describes a theoretical study on the speed of torsional elastic waves propagating in a circular rod whose material properties vary periodically as harmonic functions of the axial coordinate. An approximate solution for the phase speed has been obtained by using the perturbation technique for sinusoidal modulation of small amplitude. This solution shows that the wave speed in the nonuniform rod is dependent on the wave frequency as well as the periodic variation of the material properties. It implies that the torsional waves considered in this paper are dispersive even in the fundamental mode.

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Screw Motion and Control of Conductive Rod by Rotating a Spiral Electrodynamic Wheel (동전기 휠을 이용한 전도성 환봉의 나선형 운동과 제어)

  • Jung, Kwang-Suk
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.9
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    • pp.882-887
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    • 2011
  • A spiral electrodynamic wheel is proposed as an actuator for the contactless conveyance of a conductive rod. When rotating the wheel around the rod, a radial force, a tangential force, and an axial force are generated on the rod and cause a screw motion of the rod. The rotation of the rod is the inevitable result due to traction torque of the wheel and the unintended motion to be excluded. However, the rotating speed of the rod should be measured without mechanical contact to be cancelled out through the controller, so the electrodynamic wheel is used as a sensor measuring the rotating speed of the rod indirectly as well as an actuator. In this paper, we model the magnetic forces by the proposed wheel theoretically and compare the derived model with simulation result by Maxwell, and analyze influences on the magnetic forces by key parameters constituting the wheel. The feasibility of the conveyance system is verified experimentally.

The Machining Technique of Connecting Rod through Constant Control of Cutting Speed Method in Ball End Mill Machining (볼엔드밀 가공에서 절삭속도 일정제어기법에 의한 커넥팅로드 가공기술)

  • Kang, Myung-Chang;Jung, Young-Ho;Kim, Jeong-Suk;Moon, Sung-Jun;Kim, Kyung-Kyoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1053-1059
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    • 2002
  • The purpose of this study is to suggest how the machining technique of constant control of cutting speed can improve precision machining and tool life in high speed machining using a ball end mill. Cutting speed is changed in machining fee form surfaces such as connecting rod die. So, we don't have supreme surface form and tool life on machining. To solve this problem we should settle on optimal cutting speeds in free form surface machining. And, to improve precision machining, We must execute high speed machining methods to output optimum NC data using developed constant control of cutting speed program after modeling by CAD/CAM. In this paper, a comparison was made of the cutting precision and tool life in conventional cutting and those in connecting rod machining applying the program developed.

Stabilization of Lean Premixed Flames by a Heated Cylindrical Rod;The Role of Heat Flux (가열된 원통형보염기에 의한 희박 예혼합화염의 보염;열유속의 역할)

  • Seo, Dong-Kyu;Lee, Won-Nam
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1372-1377
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    • 2003
  • The stabilization of propane/air lean premixed flames by a heated cylindrical rod is investigated experimentally. The flame stability limits, heat flux, surface temperatures, equivalence ratios, and mixture velocities are measured in order to understand the role of heat flux or surface temperature on the flame stabilization of lean premixed flames. The flame stability limits are lowered by a heated cylindrical rod and extended even below the flammability limit of propane/air mixture when sufficient heat flux is provided. The flame stability limit decreases with the increase of heat flux or surface temperature and decreases with the higher mixture velocity. The diameter of cylindrical rod, however, dose not significantly affect the flame stability limit. The laminar flame speed has been measured for ultra lean propane/air premixed flames. The flame stabilization by a heated cylindrical rod provides the useful tool for the measurement of flame speed under very fuel-lean conditions.

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An Influence of Water Ingestion into Engine Cylinder on the Joint Reaction Force of the Connecting Rod (엔진 실린더 내 물 유입이 커넥팅로드 조인트반력에 미치는 영향)

  • Kim, Hyeong-Hyeon;Yoon, Hi-Seak;Seo, Kwon-Hee;Moon, Young-Deuk
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.4 s.97
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    • pp.79-84
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    • 1999
  • This paper focus on investigating the influence of the amount of water ingestion and the engine speed on the joint reaction force of the connecting rod in engine. The connecting rod was modelled by MSC/PATRAN, the modal informations of it were obtained by the DMAP module in the MSC/NASTRAN, and the dynamic force history was computed through the flexible multibody dynamic simulation in DADS. To analyze the joint reaction force acting on the connecting rod, the 48 cases were investigated. The engine speed varies with 200, 700, 1600, 2400rpm and the volumetric ratio of water to the combustion chamber varies with 0, 10, 20, ..., 90, 95 and 97.5% . As the engine speed decreases and the amount of water ingestion increases, the joint reaction force increase. Especially when the amount of water ingestion exceeds the 70% of the volume of the combution chamber, the joint reaction force acting on the connecting rod is over the design strength.

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Non-Contact Manipulation of Conductive Rod using Axial Magnet Wheels (축형 자기차륜을 이용한 전도성 환봉의 비접촉 조작)

  • Jung, Kwang-Suk
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.7
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    • pp.626-632
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    • 2013
  • When a conductive rod is put within rotating axial magnet wheels arranged parallel, three-axial magnetic forces generate on the rod. In some region, the forces has a property of negative stiffness, thus they can be applied to noncontact conveyance of the rod without a control load. Apart from the passive driving, the magnet wheel should be controlled for the rod to be stayed at the still state or be moved in a specified velocity. But, because a control input is just the rotating speed of the magnet wheel, the number of input is less than that of variables to be controlled. It means that levitation force and thrust force increase at the same time for increasing wheel speed, resulting from a strong couple between two forces. Thus, in this paper, a novel method, in which the longitudinal motion of the rod is controlled indirectly by the normal motion of the rod with respect to the wheel center, is introduced to manipulate the rod without mechanical contact on space.